Process for vulcanizing rubber and products obtained thereby



Patented Jan. 2, 1923.

SIDNEY m. cAnwELL, or LEONIA, NEW JER's'EY, ASSIGNOR TO THE nAUeA'rUcKFATE CHEMICAL COMPANY, A CORPORATION OF CONNECTICUT.

PROCESS FOR VULCANIZING RUBBER AND PRODUCTSOBTAINED THEREBY.

No Drawing. Application filed April 1,

To all whom it may concern.-

Be it known that I, SIDNEY M. CADWELL,

a citizen of the United States, residing at Leonia, county of Bergen,and State of New Jersey, have invented certain new and'usefulImprovements in Processes for Vulcanizing Rubber and Products ObtainedThereby. of which the following is a full, clear, and exact description.

This invention relates to vulcanizing rubber and similar materials, andto the products obtained thereby, being more particularly directed toacceleration of vulcanization by a class of organic accelerators andproductsresulting from such vulcanization.

This case is a continuation in part of my co-pending applications SerialNo. 359,808, filed February 19, 1920; Serial No. '37 9,492,

filed May 7 1920; Serial No. 417,581, filed October 18, 1920; Serial No.374,275, filed April 16, 1920; Serial No. 424,456. filed November 16.1920; Serial No. 455,490, filed March 25. 1921, and Serial No. 471,439,filed May 21. 1921. have been filed on the same date with thisapplication as divisions thereof: Serial NOS. 548,827, 548,828, 548,829,548,830 and One object of the invention is to provide a process of thekind. mentioned employing accelerators obtainable from inexpensive rawmaterials by a simple method. Another object of the invention is toprovide a proc-" ess in which accelerators of the kind mentioned may bereadily compounded with rubber, or. similar material, which shall permitof the carrying out of vulcanization at ordinary temperatures, in massesof rubber or in thin sheets while avoiding the generization. as, forexample,'takes places when sulphur chloride 18 used. Another objectvsuch as high tensile strength, resistance to The followingapplications-:-

1922. Serial No. 548,826.

is to provide a'series of products having generally desirable physicalcharacteristics,

aging. resistance to flexing, etc., and which shall vbe substantiallyfree from the odor of the vulcanizing ingredients employed' Otherobjects will in part be obvious an in part pointed out hereinafter.

The invention accordingly consists broadly I in the process, and productobtained therefrom, for treating rubber and similar ma terials, whichcomprises subjecting the rubber to a vulcanizing agent and a substancecontaining the radical RCSM,

and vulcanizing the rubber. In this formula, R represents any elementsubject to the limitation mentioned hereinafter M represents asalt-forming element orgroup or hydrogemsuch as zinc, ammonium, etc.,and is designated as representing a metal "or. being Inetallic,'or aradical SCR or a radical svmbol R in ation of acids dur ng the processof vnlcan-- v RCSM is preferably limited to any element except nitrogen;in the third group where M represents ca it this limitation is absent.In the table herein shown forming part of thespecih'catron, there isshown the broad group containing the radical RosM sub-divided into threesmaller groups which are respectively RCSM, RCSSCR, RCSCR.

M=Metal, M=SCR, M=CR etc.

under which fall RCSM,

where M is the metal and cluded, and

R'cssoR,

thiol salts are inwhere M is equal to it has been found that Mpreferably represents either zinc or mercury in the mercuric state whenvulcanization at ordinary temperatures, approximately F is carried out,and when vulcanization above ordinary temperatures, the preferred metalsare the following :-zinc, mercury, preferably in the mercuricstate,.lead, preferably in the plumbous state, cadmium, copper,preferably oxygen and sulphur in the cupric state, arsenic, preferablyin the arsenous state, manganese, preferably in the manganous state, sothat the preferred formula for the thiol salts is where M represents oneof the preferred metals given. M may be substituted by any metalprovided that one of the metals just mentioned. is present in thecombination either at some other position in the formula including or beintroduced otherwise than as part of this compound. In connection withthe other groups mentioned, namely, those represented by the formulaeRCSSCR and nose

constituting respectively the disulphide and monosulphide groups, thepresence of zinc or mercury in the mercuric state is preferable whenvulcanization at ordinary tem peratures is carried out. Whenvulcanization above ordinary temperatures is carried out the preferredmetals are the following:-zinc, mercury, preferably in the inercuricstate, lead, preferably in the plumbous state, cadmium, copper,preferably in the cupric state, arsenic, preferably in the arsenousstate, manganese, preferably in the manganous state. As noted inconnection with the first group, the metals employed with groups 2 and 3may be present in any combined form.

In the table mentioned above, R and X are shown as represented bycarbon, oxygen, nitrogen and sulphur, which are four of the moreimportant elements occurring in organic compounds.

It will be understood that the invention is not limited to thespeciesshown in the accompanying table, and that by substituting other elementsthan nitrogen, carbon, for the symbol R or X, various other species maybe formulated,

falling Within the scope of the invention. Although the various speciesdisclosed are represented as symmetrical, it will be understood thatunsymmetrical Species also fall Within the limits of the invention.

' The table is GROUP 1.

RCSM

M Metal Thiol salts.

In general, it is to be noted in connection with this group, that itsmembers are able to accelerate both hot vulcanization, that is,vulcanization at or above 240 F. and vulcanization below suchtemperatures, and that they may be used for such vulcanization in thickmasses of rubber, in thin sheets, or in cements.

The general procedure for vulcanizing employing members of this group isas follows :-l00 parts of rubber, 10 parts zinc oxide, 3 parts ofsulphur, and 0.1-3.0 parts of accelerator are mixed. If vulcanizationwith heat is employed the usual temperatures or lower may be used forperiods of thirty minutes or more to complete vulcanization. The normalor usual temperatures of hot vulcanization are 240 F. or above. If coldvulcanization is desired the mixed materials may be allowed to stand atordinary room temperature for a week or less, when vulcanization iscomplete. The procedure given above may be employed with thin or thickmasses of rubber, and in the case of cements where a solvent is usedwith the mixture, the procedure after mixing and evaporation of thesolvent, is substantially identical with that employed for thin massesof rubber. The use of materials of this group, in the manner indicated.above, will secure cold vulcanization without added bases or amines, butif such bases or amines are added, the vulcanization is accelerated.

The action of the addition of amines to materials of this class has beenfound to be as follows :The acceleration by aliphatic amines isgreatest, when approximately a half molecular weight of the amine on thebasis of the carbon disulphide content of the thiol salt is used. Anexcess of primary aliphatic amine retards the cure considerably. Anexcess of secondary aliphatic amine re tards the cure less and an excessof tertiary aliphatic amine has practically no retarding effect. Thegreater the amount of primary aromatic amine added the greater theacceleration. Dibenzyl amine has given excellent results in theacceleration of vulcanization according to the invention. Aniline hasalso given good results. Bases such as sodium hydroxide also acceleratethe action of thiol salts.

The thiol salts are particularly adapted to be used in connection withcold curing and cements. It will be understood of course as pointed outabove that they may be used in hot vulcanization and otherwise asdesired. The members of the group are preferably employed wit-hsubstances containing combined zinc, preferably zinc oxide, or one ofthe metals in combination hereinbefore enumerated. The oxides aregenerially designated as MO.

Species 1.

oosn

As a specfiic embodiment of one of the members of this group which whenemployed in a process constituting the invention has provided goodresults, the following example is cited :-100 parts of rubber, 10 partsof zinc oxide, 4 parts of zinc butyl xanthogenate, 1 part of sulphur,and two (2) parts paratoluidine, are mixed by milling in the usual way.The mixture is milled or sheeted or formed in any other way and thematerial so treated is allowed to stand for several days. vulcanizationis then completed at ordinary temperature without the application ofheat. A convenient method for vulcanization at temperatures below 240 F.consists in exposing the above mixture, milled, sheeted, or formed inany other way desired, to a temperature of ap proximately 170 F. for 60minutes, whereupon satisfactory vulcanization is secured. It will beobserved that a base, paratoluidine, has been employed here. Such abase, particularly an amine accelerates the vulcanization process,employing the various members of this species, even more rapidly,although it omitted vulcanization will take place at ordinarytemperatures. A convenient method for forming molded goods is to heatthe rubber compounded with a member of this species for a short periodin the mold, and then allow vulcanization to proceed at ordinarytemperatures.

In employing material of this species with cement, the followingprocedure may be carried out :100 parts of rubber, 10 parts zinc oxide,6 parts of zinc butyl xanthogenate, are made into a cement with 800parts of benzol, and 100 parts of rubber, 10 parts of zinc oxide, 6parts of sulphur and 6 parts of paratoluidine are made into cement with800 parts of benzol. Neither one of these cements will vulcanize atordinary temperatures on standing for several months, but if mixed inequal proportions the mixed cement or the dried rubber therefrom willvulcanize in from 24 to 48 hours in ordinary room temperature. If hightemperatures are employed vulcanization proceeds more quickly.

Zinc butyl xanthogenate is prepared as follows: 20 lbs. potassiumhydroxide sticks are dissolved in a minimum amount of hot Water. Thesolution is cooled and placed in a cool tub, and 6000 cc. carbondisulphide and 7000 cc. butyl alcohol are slowly added with stirring andcooling. Heat is evolved and the reaction mixture takes on a red color.due which is believed to be potassium butyl xanthogenate isrecrystallized from a small amount of Water. 200 grams of this potassiumbutyl xanthogenate are dissolved in a litre of Water and added to 200grams of zinc sulphate dissolved in a litre of water. The precipitatewhich forms is believed to be zinc butyl xanthogenate. It is filteredout and dried at ordinary temperature. The zinc butyl xanthogenate asthus prepared usually contains a small amount of zinc oxide, but it maybe purified until only a small per cent zinc oxide remains. Among itsproperties may be mentioned the following: It decomposes in the presenceof amines and alkalies. It is a white powder; it is soluble in about 10parts benzol; soluble in about 8 parts chloroform, somewhat solublein'carbon tetrachloride; slightly soluble in gasoline or ligroin.

In general, members of this species operate advantageously where thezinc or similar combined metal is present. Where zinc oxide is usedreduction in its proportions will produce transparent stocks.

Other members of this species falling under' the general formula givenare :-butyl xanthogenate of potassium, sodium, barium, magnesium,calcium, ammonium, iron, lead, etc.

Other members of this species are It is cooled and filtered and theresi- Potassium ethylxanthogenate CzHaOCSK Sodium ethylxanthogenate CHcOCSNa Ferric ethylxanthogenate Lead ethylxanthogenate Mercuricethylxanthogenate Potassium amylxanthogenate Zinc amylxanthogenate Zincethylxanthogenate Species 2.

oc sm' Barium ethylxanthogenate ogruoosnasoooqm j Leadmethylxanthogenate cngoc srbscoona Zinc methylaxanthogenatecmocsznscocns Linthium ethylxanthogenate C H OCSLi Magnesiumethylxanthogenate cimocsn scocgns Calcium ethylxanthogenate C HOCSCaSFOC2Hs Ammonium ethylxanthogenate CzH5OCSNH connection with theprocess included in the invention J canoe-s1; Ethyloxyester of potassiumthiolcarbonate.

- C4H9OC-SK ll Butyloxyester of potassium thiolcarbonate.

Species 5.

OCSM N it The following members 1 of this species have been employed togive good results in connection with the process included in theinvention.

Ethyl ester of allyl thiocarbamic acid CH =CHCH NH s z sC Ethyl ester ofphenylthiocarbamic acid s c.1158 Butyl ester phenylthiocarbamic acidCEHSNH Species 5.

m zsm The following members of this species have been employed to givegood results in connection with the process included in the invention:

Lead dithiophenylacetate o H5cH,c-s1 bs-ccH,c m n 1| Lead dithiobenzoatec.mc s1=bs-cc,m u n Zinc dithiobenzoate CgH5fi-SZHS-CC5H5 Cadmiumdithiobenzoate C H5GSCdSCC H Mercurous dithiobenzoate l C H5-SHg Cupricdithiobenzoate cfim scusmosm Potassium dithiobenzoate c mp-SK Leaddithioacetate cmp-sPbs-com 7 ll s s or.

Lead dithiobrombenzoate Zinc dithiobenzoate is preferably employed asfollows: 100 parts of rubber are mixed with 10 parts of zinc oxide, 3parts of sulphur and part of zinc dithiobeninvention Lead thiobenzoateqHsfr-srbs-r icm Potassium thioacetate cmosx.

Lead thiobutrate c mc-sriis-coini Species 7.

COSM

The following members of this species have been employed to give goodresults in connection with the process included in the inventionThiobenzanilide.

Species .9.

scsM SCSM The following member of this species has been employedto givegood results in connection with the process included in this 1nvention:zncos2 Zinc dithiocarbonat'e.

Species 13.

NICSM zoate, and vulcanization is accomplished in a mold at 40 lbs.steam pressure for 30 minutes.

The following members of this species Disclosure of this species is madeand claimed in copending application Serial No. 374,275, filed April 16,1920.

The members of this class include: Potassiumorthomethylphenylenedithiocarbamate Calcium paramethylphenylenedithiocarbamate Magnesium orthomethylphenylenedithiocarbamate g a I owmctumml-sii,

Copper ethylphenyldithiocarbamate Zinc methylphenyldithiocarbamate v Ncszn,

on, E

Species 14.

NCSM

The following member of this species has been employed to give goodresults in 0on nection with the process included in this 1nvention:

Zinc diethylthiocarbamate Speciesl'. NtEBM The following members of thiss ecies have been employed to give good resu ts in connection with theprocess included in this invention Ethylphenylthiourea ammo-s11 C0135Dimethylphenylthiourea ammo-s1:

, a t GROUP II.

R'CSSCR Dlsulphldes.

In general, members of this group exhibit similar properties to thoseset forth in connection with Group I. The rocedure followed forvulcanlzation emp oying members of this group and the quantities of theingredients in eneral are the same as are employed in Gi'oup I. Inconnection with curing at ordinary temperatures, it is pointed wt thatsuch'curing is effected in a slightly longer time than in connectionwith members of Group I. The group possesses the advantage that itsmembers may be introduced into bulk rubber with practically no danger ofprevulcanization or burning when milled. As pointed'out above, acombined metal preferably in the class has been found to be as follows:

The acceleration by aliphatic amines is greatest when approximatelythreeuarters molecular weight of the amine on t e basis of the carbondisulphide content of the compound is used. 'An excess of primaryaliphatic amine retards the cure considerabl An excess of secondaryaliphatic amine retards the cure'less. The greater the amount of primaryaromatic; amine added, the greater the acceleration. Tertiary amineshave substantially no effect. Dibenyl amine has given excellent resultsin the acceleration of vulcanization according 'to the invention.Aniline has also given good results. Sodium hydroxide also acceleratesthe action of disulphides.

Species 17.

As an example of the specific procedure employing a member of thisgroup, 100 parts of rubber, 10 parts of zinc oxide, 3 arts of sulphurand two arts O-nor'mal butyl 'thiocarbonic acid isulphide, are mixed bymilling and vulcanization is accomplished by placing the material in amold and subjecting to steam pressure at 40 pounds per square inch for10 minutes.

The cure may be continued several times as long without bad effects andthe vulcanization may be carried out in open air or steam with e uallygood results. The time of cure is 0% course dependent on the thicknessofthe rubber and will va with diflerent "kinds of stock. This aoce eratoris however articularly active and vulcanization is qulckly obtained anda stock produced which has excellent tensile properties and very littleodor. t The oxy normal but 1 thiooarbonic acid disulphide is prepared byadding one ram molecular weight of. butyl alcohol, an one gram molecularweight of carbon disulphide,to a solution of two gram molecular wei htsof potassium hydroxide, dissolved to o'rm a 50% aqueous solution, andconstantly stirring the mixture and cooling. Needles of potassium butylxantho 'enato separate out and can be recrystallize from water oralcohol. This salt is dissolved in water and oxidized by the addition ofaquepared but it is amass thereby obtaining a clear light re dish brownoil having very little odor. Other members of this class may besimilarly preinted out that the claims are not limits to the hereindescribed method of preparation since these accelerators ma intende inthe claims to cover processes of vulcanization employing acceleratorshaving constitutions'similar or identical with those prepared by theabove described method.

vulcanization at a low temperature, 100' parts of rubber, .10 parts ofzinc oxide, '1 part of sulphur, parts of O-normal butyl thiocarbonicacid dlsul hide, and 1 part of aniline" are mixed bymilling and allowedto remain at ordinary room temperature for a vu canization is efiected.I y varym the accelerator and the amine tor various resuts may beproduced and the temperatures. necessary 'forvulcanization may belikewise varied. In the caseofsome of the accelerators of this class,low temperature vulcanization may be accomplished without the aid of anamine; It will be ap parent that when low tem rature vulcani zation iscarried out witht e aid-of the several members of the class, theproportions of the example just given may. be varied to suit therequirements of the particular caseand the stock to be treated. By theterm low tem rature is meant temperatures ranging rom room temperatureor lower to nearly 240 F.

The above accelerator is a preferred member of a group of compoundswhich are able to produce approximatel equally good .re'-- sults when aed as acce erators in vulcanizing rubber and among the members of thisgroup may be mentioned the followin O-methylthioearbomc acid disulphi eomooss'cocm O-ethylthiocarbonic acid disulphide cafieOlifidfiO rO-amylthiocarbonic acid disulphidedsnocsscocin ly vary in their efiectsaccording to the nature of the alkyl' or similar group, and they may beselected for the requirements of a particular case. p

ing high tensile strengt g be otherwise prepared and it is '"an .e cientm-ixture.- The raw materials .from which the-accelerators are preparedweek a proximately, whereupon a satisfac- I compounding ingredientsonthe mi 1, which B the use of the above mentioned out burnln orprevulcani'zation on the mill-and ru ber products are reduced havagingqualities and very little odor. -The fact that many of the members oftheabovemap are oily substances renders their ad 'tion to the compoundingingredients on the mill an eas o eration and results in a very uniformare moreover cheap and the process of manufacture simple. lit istherefore evident that the objects of the invention above enumeratedhave been achieved.- Y

A particular meritof these accelerators is that they will efiect coldvulcanization, and

that they will do so withoutregenerating fin V acid which is anadvantage not possesse sulphur chloride. for this e nt nerates Hbl. Theymay be added irect to the is also impracticable with sulphur chloride.In general the members of this ecies are oils and home may be more reaily com pounded than solid materials by milling;

Seeder: Z8.

iiil"- The following member of this species has been emplo ed to givegood results in con- :nection W1 the process included in the inventien:

Dibutyloxyester of carbonyldisulphide clmoo-sscoclm Species 31.

oossoc The following members of this species have been employed to givegood results in connection with the process'included in the inventionThiobenzoyldisulphide mamas-sects,

Thiophenylacetyldisulphide 4 camomc-s-socmcem Thioacetyldisulphidecmc-ssccmice .Speez'eaZZ. Gnour III.

' 695500 ncscn (i ii M-on The following members of this species havebeenem-ploycd to give good results 1n connection wit-h the processincluded 1n the MmwsulPhldee invention Acetyldisulphldc, cuii ss cnBenzoyldisulphide amp-s-Spoan Species 95.

The-following member of this species has I been employed to give goodresults in conprocess included in thenect-ion with the L i Members ofthis class include: Dimethyldiphenylthiuramdisulphide on. Nc-s-s-o-N cm;0.115 v Diet hyldiphenylthiuramdisulphide 2 lsl C H5Diparamethylphenylenedimethylthiuramdisulphide The above members were.disclosed and claimed in my copending application Serial No. 374,275,filed April 16, 1920, and now appear in my copending application SerialNo. 424,456, filed November 16, 1920.

Species 30.

NCSSCN v The following member of this species has been employed to givegood results in connection with the process included in the inventionTetraethylcarbamyldisulphide (0:1 9:11 0-SSCN( :Ht):

ll ii In general, the members of this. group are similar in their actionin the process constituting this invention to the members of Groups Iand II, except that the members of fected on the. mills in the usual wayand the product being cured in the mold under 40 lbs. steam.pressure forten minutes. Vulcanization may be effected in open steam or air withapproximately similar results and the time of vulcanization may beprolonged without damage to the stock although of course the time ofvulcanization will be dependent on the thickness of the goods. Theresulting product 'is'odorless and colorless and has the usual excellentproperties of rubber cured with sulphur.

The action of the addition of primary and secondary amines to materialsof this class has been found to be as follows: The acceleration byaliphatic amines is greatest when approximately one and one-half timesthemolecular weight of the amine on the basis of the molecular weight ofthe compound is used. An excess of primary aliphatic amine retards thecure considerably. An excess of secondar' aliphatic amine retards thecure less. ,T e greater the amount of primary aromatic amine added, thegreater the acceleration. Tertiary amines have substantially no effect.'Dibenzyl amine has given excellent results in the acceleration ofvulcanization according to the invention. Sodium hydroxide alsoaccelerates the action of monosulphides.

Species 38.

ccscc The following member of this species has been employed to givegood results in connection with the process included in the invention:-

Thiobenzoic anhydride cane-seem;

also unsymmetrical compounds occupying midway position between Species37 and 38 Benzoylb utylxanthogenate C5H5CSCOC4HQ l v I b Benzoyl'ethylxanthogenate canto-so emn Species 45.

NCSCN Members of'this class include: D. i p h enyldimethylthiurammonosulphlde (mentioned above.)

CHQ L E CHS Tetramethylthiurammonosulphide I NoscN 011 g g cmTetraethylthiurammonosulphide C2H5\NCSCN/C2H5 CZHE/ g g \C2H5Diphenyldiethylthiurammonosulphide G6H5\|\IGSGN/C5H5 0211/ g A c HtTetrapropylthiurammonosulphide csn1 can;

C3H1/ li i C3H1 E t h yl p h e nyldimethylthiurammonosulphide CH3\ C2H5cH3 i L o H5 Methylp-henylethylthiurammonosulphide G5H5\ H 0211/ NFSENCH8 Phenylmethylcarbamylester of phenylmethyldithiocarbamicacid cnN-piperidyl-S-benzoyldithiourethane In general, the acceleratorsincluded in the three groups herein set forth are obtainable frominexpensive raw materials by simple methods. The members of Group IIImay be used, in general, safely without great danger of prevulcanizationin the milling process. The members of the various groups may beemployed generally for vul- Eli! tutes, synthetic rubber, balata, guttapercha,

etc. may be similarl treated instead of rubber and it is inten ed tocover such processes in the claims.

It will be noted in connection with the various members of Group I thatthe ability to accelerate vulcanization at temperatures below normal hotvulcanization temperature for instance at ordinary temperatures variesin accordance with the species selected, but in general, this group ashas been pointed out, efi'ects vulcanization at ordinary temperatures.Groups II and III also include species which accelerate vulcanization atordinary temperatures, only slightly. In general the various experimentsmade in connection with the three groups indicate that nonnitrogenousaccelerators efiect vulcanization at ordinary temperatures. The productsobtained in the various groups provide, in general, desirable physicalcharacteristics, such as high tensile strength, resistance to aging,resistance to flexing, etc., and in general are free from the odor ofvulcanizing in others the objects of the invention above enumerated areachieved.

It will be understood that the invention disclosed in co-pendingapplication Serial No. 4l,691, filed February 1, 1921, may be employedin connection with the accelerators disclosed and included in theinvention of the present application.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit thereof, it will be understoodthat I do not intend to in set forth except as indicated in the appendedclaims.

Each of the substances enumerated herein as members of the variousspecies hasbeen employed in the vulcanization of rubber and has beenfound to accomplish'vulcanization as indicated.

' Having thus described my invention, What I claim and desire to protectby Letters Patent is:

1. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcanizing agent, and an acceleratorcomprising the group and vulcanizing the rubber.

2. A process of vulcanizing rubber or similarmaterial which comprisescombining with the rubber'a vulcanizing agent, and an acceleratorcomprising the group RCSM ' gredients. It will thus be seen that amonglimit myself to the specific embodiment herein the presence of acombined metal M, and vulcanizingthe rubber.

3. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a'vulcanizing agent, a base, and anaccelerator comprising thegroup RCSM,

and viilcanizing the rubber.

4. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcanizlng agent, a base, and anaccelerator comprising the group RCSM,

in the presence of a combined metal M, and vulcanizing the rubber. I

;5. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a Vulcanizing agent, an amine, and anaccelerator comprising the group RCSM,

and vulcanizing the rubber.

6. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcanizing agent, an

amine, and an accelerator comprising the group RCSM,

in the presence of a combined metal M, and vulcanizing the rubber.

7. A process of vulcanizing rubber or similar material which'comprisescombining with the rubber'a vulcanizing agent, and an acceleratorcomprising the group OGSM,

and vulcanizing the rubber.

8. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcaniz'ing agent, and an acceleratorcomprlsing. the group OCSM with the rubber a vulcanizing agent, and

an accelerator comprising the grou R'csscR;

and vulcanizing the rubber.

11. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcanizing agent, and an acceleratorcomprising the radical oossco,

and vulcanizing the rubber.

12. A process of vulcanizing rubber or similar material which comprisescombining with the rubber 'a vulcanizing agent, and

an accelerator comprising the radical oossco in the presence of acombined metal M and vulcanizing the rubber.

13. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcanizing agent and an acceleratorcomprising the radical ocssco.

in the presence of MO, and vulcanizing the rubber.

14. A process of vulca-nizing rubber or similar material which comprisescombining the rubber with a vulcanizing agent and an acceleratorcomprising the radical and an amine, and vulcanizing the rubber.

15. A process of vulcanizing rubber or similar material which comprisescombining the rubber with a vulcanizing agent and an acceleratorcomprising the radical OICSSCO and an amine, in the presence of acombined metal M, and vulcanlzing the rubber.

16. A process of vuloanizing rubber or similar material which comprisescombining with rubber a vulcanizing agent and an accelerator comprisingthe radical in the presence of combined zinc, and vulcanizing therubber.

17. A process of vulcanizing rubber or similar material which comprisescombining the rubber with a vulcanizing agent and an acceleratorcomprising the radical and an amine, in the presence of combined zmc,and vulcanizing the rubber.

ocssoo and an aromatic amine, in the presence of comb ned zinc, andvulcamzing the rubber. l9.-A process of vulcanizing rubber orsimilarfmaterial which comprises combining the rubber with a vulcanizingagent and an accelerator comprising the radical oossoo and an aromatieamine, in the presence of zinc 0xide,-and-vulcan1z1ng the rubber.

' 20. A process of vulcanizing rubberorsimilar material-which comprisescombining with the rubber. an organic disulphide in the presence ofan'jamine and a combined metal M, andvulcanizing the rubber.

QL-A process of vulc-anizing rubber or similar materialwhich comprisescombining with the rubber an organic disulphidein the presence of anamine and combined zinc, and vulcanizing. the rubber.

22. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcanizing agent, a base and an acceleratorcomprising the group in the presence of a combined metal M, andvulcanizing the rubber at a temperature below the normal hot vulcanizingtemperature.

24. A process of vulcanizing rubber or similar material-which comprisescombining withthe rubber a vulcanizing agent and an acceleratorcomprising the group inthe presence of a combined metal M, and

vulcamzing the rubber at a. temperature below the normal hot vulcanizingtemperature.

25.'A.; process 'of vulcanizing rubber or simila with It e rubber afyulcanizing agent, M O

and an eccelerator' comprising the group OCSM, Q

fateriali-which comprises combining.

and ulca-nizing the rubber at a temperature below the normal hotvulcanizing temperature.

26. A process of vulcanizing rubber or similar material which comprisescombining the rubber with a vulcanizing agent and an acceleratorcomprising the radical OCSSCO and an amine, in the presence of acombined accelerator comprising the radical at a. temperature below thenormal hot vulcanizing temperature.

28. A process of vulcanizing rubber or similar material which comprisescombining the rubber with a vulcanizing agent and an acceleratorcomprising the radical ocssoo and an aromatic amine, in the presence ofzinc oxide, and vulcanizing the rubber at a temperature below .thenormal hot vulcanizing temperature.

29. A process of vulcanizing rubber or similar material which comprisescombining with the rubber an organic disulphide in the presence of anamine and a combined metal M, and vulcanizing the rubber atatemperaturebelow the normal hot vulcanizing temperature.

30. A process of vulcanizing rubber or similar material which comprisescombining with the rubber an organic disulphide in the presence of; anamine and combined zinc, and vulcanizing the rubber at a temperaturebelow the normal hot vulcanizing temperature.

31. A process oftreating rubber or similar material which comprisescombining it with a vulcanizing agent, a thioca-rbonic acid disulphideand a combined metal M, and vulcanizing the rubber.

32. A process of treating rubber or similar material which comprisescombining it with a vulc-anizing agent, a thiocarbonic acid disulphide,a combined metal M and an 'amine having a replaceable ammoniacalhymoniacalhydrogen, and vulcanizing the rubber.

34. A process of treating rubber or similar material which comprisescombining it with a vulcanizing agent, oxy normal butyl thiocarbonicacid disulphide, zinc in combination and an amine having a replaceableammoniacal hydrogen, and vulcanizing the rubber. H

35. A process of treating rubber or similar material which comprisescombining it with a vulcanizing agent, oxy normal butyl thiocarbonicacid disulphide, zinc in combination, and an aliphatic amine having areplaceable ammoniacal hydrogen, and vulcanizing the rubber.

36. A process of treating rubber or similar material which comprisescombining it with a vulcanizing agent, oxy normal butyl thiocarbonicaciddisulphide, zinc oxide and dibenzyl amine, and vulcanizing the rubber.

37. A process of vulcanizing rubber or similar material which comprisestreating the rubber with a non-nitrogenous carbon disulphide derivativein the presence of a vulcanizing agent and a combined metal M, andvulcanizing the rubber at a temperature below the normal hotvulcanization temperature.

38. A process of vulcanizing rubber or similar material which comprisestreating rubber with a non-nitrogenous carbon oXy sulphide derivativeand a metal M, and vulcanizing the rubber.

39. A process of vulcanizing rubber or similar material which comprisestreating the rubber with a non-nitrogenous carbon disulphide derivativein the presence of sulphur, and a combined metal M, and vulcanizing therubber at a temperature below the normal hot vulcanization temperature.

40. A process of vulcanizing rubber or similar material which comprisestreating the rubber with a non-nitrogenous carbon oxy sulphidederivative in the presence of sulphur and a metal M, and vulcanizing therubber.

41. A vulcanized rubber derived from rubber or similar material combinedwith an accelerator comprising the group RCSM,

and a vulcanizing agent.

42A vulcanized rubber derived from rubber or similar material combinedwith an accelerator comprising the. group RCSM in the presence of acombined metal M, and a vulcanizing agent.

43. A vulcanized rubber derived from rubber or similar material combinedwith a base, and an accelerator comprising the group ntlism,

and a vulcanizing agent.

44. A vulcanized rubber derived from rubber or similar material combinedwith a base and an accelerator comprising the group RCSM,

in the presence of a combined metal M, and a vulcanizing agent.

45. A vulcanized rubber derived from rubber or similar material combinedwith an amine, and an accelerator comprising the group seen,

and a vulcanizing agent.

46. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent, an amine and an accelerator comprising thegroup.

RCSM,

in the presence of a combined metal M.

47. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the group OCSM.

48. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator cornprising the group OCSMin the presence of a combined metal M.

49. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent, M O and an accelerator comprising the groupOCSM.

52. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicalocssco in the presence of a combined metal M.

53. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicalocssoo in the presence of MO.- y

54. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicaloossoo and an amine.

55. A vulcanized rubber derived from rubber'or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicalOtFSSCO and an amine, in the presence of a combined meta-l M. 56. Avulcanized rubber derived from rubber or similar material combined witha vulcanizing agent and an accelerator comprising the radical oossco inthe presence of combined Zinc.

57. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicalocssco and an amine, in the presence of combined zinc.

58. A vulcanized rubber derived from rubber or similarm'aterial'combined with a vulcanizing agent and an acceleratorcomprising the radical ocssoo and an aromatic amine, in the presence ofcombined zinc.

59. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizirig agent and an accelerator comprising the radical Qocssco I and an amine.

and an arou'latic amine, in the presence of zinc oxide.

(30. A vulcanized rubber derived from rubber or similar materialcombined with an organic disulphide in the presence of an amine and acombined metal M.

61. A vulcanized rubber---derived from rubber or similar materialcombined with an organic disulphide in the presence of an amine andcombined zinc.

62. A rubber vulcanized at a temperaturebelow the normal hotvulc-anizing-temperature derived from rubber or similar materialcombined with avulcanizing agent, a base and an accelerator comprisingthe group RZSM in the presence of a combined metal M.

63. A rubbervulcanized at a temperature below the normal hot vulcanizingtemperature derived from rubber or similar material combined with avulcanizing agent, an amine and an accelerator comprisingthe group RCSMOCSM.

66. A rubber vulcanized at a temperature below the normal hotvulcanizing temperature derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicalOCSSFO in the presence of a combined metal M. I

67. A rubber vulcanized at a temperature below the normal hotvulcanizing temperature derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicaloossco and an aromatic amine in the presence of combined zinc. V

(38. A rubber vulcanized at a temperature below the normal hotvulcanizing temperature derived from rubber or similar material combinedwith a vulcanizing agent and an accelerator comprising the radicalocssoo i and an aromatic amine. in the presence of zinc oxide.

69. A rubber vulcanized at a temperature below the normal hotvulcanizing temperature derived from rubber or similar material combinedwith an organic disulphide in the presence of an amine and a combinedmetal M.

'70. A rubber vulcanized at a temperature below the normal hotvulcanizing temperature derived from rubber or similar material combinedwith an organic disulphide in the presence of an amine and combinedzinc.

71. A. vulcanized rubber derived from rubber or similar materialcombined with a vulcanizing agent, a thiocarbonic acid di sulphide and acombined metal M.

72. A vulcanized rubber derived from rubber or similar material combinedwith a vulcaniziug agent, a thiocarbonic acid disulphide. a combinedmetal M and an amine having a replaceable ammoniacal hydrogen.

73. A vul'anized rubber derived from rubher or similar material combinedwith a vulcanizing agent. an alkylated thiocarbonic acid disulphide. acombined metal M and an amine having a replaceable ammoniacal hydrogen.

H. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent. oxy normal butyl thiocarbonic acid disulphide.zinc in combination and an amine having a replaceable ammoniac-alhydrogen.

75. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent, oXv normal butyl thiocarbonic acid disulphide,zinc in combina tion, and an aliphatic amine having a replaceableammoniacal hydrogen.

76. A vulcanized rubber derived from rubber or similar material combinedwith a vulcanizing agent. oxy normal butyl thiocarbonic acid disulphide.zinc oxide and dibenzyl amine.

77. A vulcanized rubber derived from rubber or similar material treatedwith a non nitrogenous carbon disulphide derivative in the presence of avulcanizing agent and a combined metal M at a temperature below thenormal hot vulcanization temperature.

78. A vulcanized rubber derived from rubber orsimilar material treatedwith a nonnitrogenous carbon oxy sulphide derivative and a metal M.

79. A vulcanized rubber derived from rubber or similar material treatedwith a non-.

nitrogenous carbon disulphide derivative in the presence of sulphur, anda combined metal M at a temperature below the normal hot vulcanizationtemperature.

80. Avulcanized rubber derived from rubher or similar material treatedwith a nonnitrogenous carbon oxy sulphide derivative in the presence ofsulphur and a metal M.

81. A process of vulcanizing rubber or similar material which comprisescombinmg with the rubber a vulcamzmg agent and an accelerator comprisingthe group RCSM in the presence of a combined metal M. and vulcanizingthe rubber at approximately 70 F.

82. A process of vulcanizing rubber or similar material which comprisescombining with the rubber a vulcanizing agent and an acceleratorcomprising the radical RfSSCR I ll 4 material combined with avulcanizing agent and an accelerator comprising the group RCSM in thepresence of a combined metal M.

85. A rubber vulcanized at a temperature of approximately 70 F. derivedfrom rubber or similar material combined with a vulcanizing agent and anaccelerator comprising the radical in the presence of a combined metalM.

86. A rubber vulcanized at a temperature of 70 F. approximately derivedfrom rubber or similar material combined with a vulcanizing agent, oxynormal butyl thio- 1,440,962 r in? i A- l nized rubber derived fromcarbomc acld dlsulphlde, Zmc m combma rubber or ii ffilar materialcombined with A rocess for treating rubber or simi sulphur, oxy normalbutyl th ocarbomc acid 10 lar matei ial which comprises combining itdlsulphide and zinc 1L1 izqomb inatfiims 30th 5 with sulphur, oxy normalbutyl thiocarbtomo d slgiegiatclilewggor ew or 'd disul hide and zinc inoombina ion, ay 0 ar L. ii d Vulcaziizing the rubber. SIDNEY M. CADWEL(Certificate of Correction. Patent No. 1,440,962. Granted January 2,1923, to

SIDNEY M. CADWELL. It is hereby certified that error appears in theprinte numbered patent requiring correction as follows: Pmethylaxanthogenate read metkg Zwzmthogenate, Linthium read Lithiumpage9, lines 121 to 12 Thioacetyldisulphide and insert instead dspecification of the aboveage 5, line 46, for the word and line 50 forthe word 4:, strike out the formula for CHaC SSOCH4:

page 10, line 86, for the word dip henyldine read diphenyldime- 62, inthe formula below the double bond for the letter 64, strike out theformula and insert instead page 15, claim 5 read an; same page,cla1mOCSM and that the said Letters Patent should be read with thesecorrections therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 24th day of July, A. D.- 1928.

[seen] WM. A. KINNAN,

Acting Commissioner of Patents.

